Static mixing device for mixing natural gas and hydrogen uniformly and working method thereof

Abstract

The application discloses a static mixing device for uniformly mixing natural gas and hydrogen, and a working method thereof, and relates to the field of hydrogen mixing and conveying of natural gas pipelines. In the device, each flow channel hole is fixedly provided with a twist unit and a turbulence unit. The twist unit comprises a plurality of twist elements which are fixedly arranged in sequence. Each twist element is formed by a first twist piece and a second twist piece which are fixedly and symmetrically arranged on the central axis of the flow channel hole. The turbulence unit comprises a plurality of turbulence elements which are fixedly arranged in sequence. Each turbulence element comprises a horizontal turbulence piece and a vertical turbulence piece. The horizontal turbulence piece comprises an elliptical central horizontal turbulence layer and auxiliary horizontal turbulence layers which are symmetrically arranged above and below the central horizontal turbulence layer. The vertical turbulence piece comprises an elliptical central vertical turbulence layer and auxiliary vertical turbulence layers which are symmetrically arranged above and below the central vertical turbulence layer. The mixing effect and the gas uniformity are significantly improved.

Description

Technical Field

[0001] This invention relates to the field of hydrogen-mixed transportation in natural gas pipelines, specifically to a static mixing device and its working method for uniformly mixing natural gas and hydrogen. Technical Background

[0002] With the ongoing transformation of the energy structure, especially the increasing maturity of renewable and clean energy technologies, hydrogen energy, as a green and low-carbon alternative energy source, is gradually gaining wider application. Against this backdrop, the technology of co-transporting natural gas and hydrogen has become a hot topic in the energy sector. This technology can not only effectively reduce carbon dioxide emissions and promote greenhouse gas emission reduction, but also drive the development of hydrogen energy and the optimization of the energy structure. The co-transportation of hydrogen and natural gas not only helps reduce environmental pollution but also improves energy utilization efficiency. Therefore, ensuring both the effectiveness of the co-transportation process and its high efficiency and safety has become a critical issue that urgently needs to be addressed.

[0003] Blending hydrogen with natural gas for transportation, while achieving clean energy utilization, also places more stringent demands on equipment. To ensure uniform mixing of natural gas and hydrogen and prevent gas instability or stratification during pipeline transportation, designing equipment capable of efficient mixing over a wide flow rate range and under variable flow conditions is crucial. Improving gas mixing efficiency, reducing equipment energy consumption, and ensuring long-term stability and reliability have become core issues that urgently need to be addressed in natural gas-hydrogen mixing technology.

[0004] Currently, in the field of gas mixing, common equipment types include dynamic mixers and static mixers. Dynamic mixers utilize external mechanical devices or energy sources (such as turbines, agitators, etc.) to promote gas mixing. While they can improve mixing efficiency to some extent, their drawbacks are also significant, including complex structure, high energy consumption, and high equipment maintenance costs. Furthermore, the operating efficiency of dynamic mixers is typically affected by changes in airflow velocity and pressure, especially in large-scale, high-flow-rate applications, where the operation of dynamic devices can lead to decreased efficiency or even malfunctions.

[0005] Compared to dynamic mixers, static mixers have gradually become the mainstream choice in gas mixing due to their simple structure, stable operation, high energy efficiency, and low maintenance requirements. Static mixers use internal stationary elements, such as spirals, meshes, or baffles, to alter the flow path and turbulence of the gas stream, effectively promoting the mixing of different gas components. Their main advantages include no need for an external power source, low energy consumption, high economic efficiency, wide applicability, and uniform gas mixing. However, traditional static mixers struggle to adapt to complex mixing conditions involving gases with significantly different physicochemical properties, such as natural gas and hydrogen, under various mixing ratios, flow rates, and velocity fluctuations. For example, in SV-type static mixers, the SV element is a cylinder composed of a series of corrugated plates. When natural gas and hydrogen flow in, the mixing uniformity is limited, and pressure loss is high, resulting in low mixing efficiency and poor mixing uniformity. Summary of the Invention

[0006] To address the problems existing in the prior art, this invention provides a static mixing device and operating method for uniformly mixing natural gas and hydrogen, which solves the problems of low uniformity and large pressure loss in SV-type static mixers when mixing natural gas and hydrogen. By optimizing the structure and arrangement of the mixing unit and combining it with flow channel holes, it can not only meet the needs of efficient gas mixing and stable operation under complex working conditions with different flow rates, velocities and input pressures, but also significantly improve the mixing effect and gas uniformity.

[0007] A static mixing device for uniformly mixing natural gas and hydrogen includes an inlet pipe, a static mixing unit, and an outlet pipe that are sequentially and fixedly connected.

[0008] The air intake pipe is provided with a natural gas inlet and a hydrogen inlet. The static mixing unit has several flow channel holes that run through both sides of the static mixing unit along its own length. Each flow channel hole has a torsion unit and a turbulence unit fixed at intervals on its inner wall.

[0009] The torsion unit includes several torsion elements that are sequentially and parallelly overlapped and fixed. Each torsion element is formed by two semi-circular first torsion plates and second torsion plates of the same diameter that are symmetrically and vertically overlapped along the central axis of the flow channel hole. The turbulence unit includes several turbulence elements that are sequentially and parallelly spliced ​​and fixed. Each turbulence element includes a horizontal turbulence element and a vertical turbulence element. The horizontal turbulence element includes an elliptical central horizontal turbulence layer and auxiliary horizontal turbulence layers that are symmetrically distributed vertically along the central horizontal turbulence layer. The vertical turbulence element includes an elliptical central vertical turbulence layer and auxiliary vertical turbulence layers that are symmetrically distributed vertically along the central vertical turbulence layer. The central horizontal turbulence layer, the auxiliary horizontal turbulence layer, the central vertical turbulence layer, and the auxiliary vertical turbulence layer are all spliced ​​together by several turbulence strips at intervals. The central horizontal turbulence layer and the central vertical turbulence layer are inserted and fixed perpendicularly to each other along the central axis of the flow channel hole.

[0010] Preferably, the intake pipe includes a first pipe and a second pipe, and the outlet pipe includes a third pipe and a fourth pipe. The first pipe and the fourth pipe have the same inner and outer diameters, and the second pipe and the third pipe have the same inner and outer diameters. The outer diameter of the first pipe is smaller than that of the second pipe. A first arc-shaped transition section is provided at the junction of the first pipe and the second pipe, and a second arc-shaped transition section is provided at the junction of the third pipe and the fourth pipe. This forces the airflow to flow along different paths, thereby promoting the forced mixing of the two gases and further improving the mixing effect. The first arc-shaped transition section and the second arc-shaped transition section have the same bending angle, both ranging from 5 degrees to 25 degrees.

[0011] Preferably, the static mixing unit is a cylindrical, regular triangular prism, regular square prism, or regular hexagonal prism pipe. The two ends of the pipe are connected to the air inlet pipe and the air outlet pipe respectively through two pairs of mutually aligned flanges. Each pair of mutually aligned flanges has a number of bolt holes evenly opened along the circumferential direction, and a corresponding bolt is installed in each bolt hole.

[0012] Preferably, the inner wall of the flow channel hole is provided with internal threads, and the first torsion plate, the second torsion plate, the central horizontal turbulence layer, and the central vertical turbulence layer are engaged in the internal threads;

[0013] The flow channel holes are evenly distributed in 3-17 portions along the cross-section of the static mixing unit. The hole diameter is 3%-13% of the cross-sectional specification of the static mixing unit. The center distance between adjacent flow channel holes is 4%-20% of the cross-sectional specification of the static mixing unit. When the cross-section of the static mixing unit is circular, the corresponding specification is the diameter. When the cross-section of the static mixing unit is an equilateral triangle, a square, or a regular hexagon, the corresponding specification is the circumcircle diameter.

[0014] Preferably, the first twist plate and the second twist plate are both vertically distributed, the center of the straight edge of the first twist plate and the center of the straight edge of the second twist plate are fixed, the included angle between the straight edge of the first twist plate and the straight edge of the second twist plate is 30°-45°, the first twist plate is located at the bottom, and the included angle between the straight edge of the first twist plate and the central axis of the flow channel hole is 45°-65°.

[0015] Preferably, the spacing between two adjacent first or second torsion plates is 0.1%-0.8% of the length of the static mixing unit, the front end of the straight edge of the second torsion plate is fixed to the front end of the straight edge of the previous first torsion plate, and the rear end of the straight edge of the second torsion plate is fixed to the rear end of the straight edge of the next first torsion plate.

[0016] Preferably, the two surfaces of the central transverse spoiler, the auxiliary transverse spoiler, the central vertical spoiler, and the auxiliary vertical spoiler are all uniformly distributed with dot-like protrusions.

[0017] Preferably, the major and minor axes of the central horizontal spoiler and the central vertical spoiler are equal, the auxiliary horizontal spoiler and the auxiliary vertical spoiler are both single layers, one end of the auxiliary horizontal spoiler and the auxiliary vertical spoiler are both arc-shaped, and the other end of the auxiliary horizontal spoiler and the auxiliary vertical spoiler are both straight lines. The arc-shaped end of the upper auxiliary horizontal spoiler corresponds to the straight end of the lower auxiliary horizontal spoiler, and the arc-shaped end of the right auxiliary vertical spoiler corresponds to the straight end of the left auxiliary vertical spoiler. The size of the auxiliary horizontal spoiler is smaller than that of the central horizontal spoiler, and the size of the auxiliary vertical spoiler is smaller than that of the central vertical spoiler.

[0018] Preferably, the foremost baffle strip of the central vertical baffle layer of the latter baffle element is fixed to the last baffle strip of the central horizontal baffle layer and the auxiliary horizontal baffle layer of the former baffle element, and all the central horizontal baffle layers and central vertical baffle layers in the baffle unit are distributed flush.

[0019] The spacing between two adjacent torsional units or between a torsional unit and a turbulence unit in each flow channel is 6%-13% of the length of the static mixing unit.

[0020] A method for operating a static mixing device for uniformly mixing natural gas and hydrogen is disclosed. Natural gas flows in through a natural gas inlet, and hydrogen flows in through a hydrogen inlet. They then enter corresponding torsion and turbulence units through various flow channels. The first and second torsion plates gradually guide the airflow to rotate, disperse, and recombine. Horizontal turbulence components disrupt the axial flow of the airflow, generating lateral turbulence. Vertical turbulence components, arranged in a staggered manner, further disrupt the radial distribution of the airflow, enhancing the mixing depth and uniformity. This ensures that natural gas and hydrogen are fully contacted and uniformly mixed within the static mixing unit. The mixed gas then flows out through the outlet, achieving efficient and uniform mixing of natural gas and hydrogen.

[0021] Compared with the prior art, the present invention has the following beneficial technical effects:

[0022] This invention discloses a static mixing device for uniformly mixing natural gas and hydrogen. Each flow channel is alternately arranged with torsion units and turbulence units along the airflow direction, forming a multi-stage mixing unit. By enhancing the synergistic effect of axial rotation, radial disturbance, and lateral turbulence, the device effectively reduces fluid stratification and maintains a highly efficient mixing state of the airflow. This allows for good mixing results under complex operating conditions with different flow rates, velocities, and input pressures. The mixed gas maintains good uniformity, achieving efficient and uniform blending of natural gas and hydrogen. The arrangement of the flow channels closely matches the airflow path, ensuring a stable and uniform mixing effect when the airflow passes through the static mixing unit, thereby guaranteeing the optimal blending efficiency of natural gas and hydrogen. The torsion element's structural design forms a certain angle with the airflow direction along the direction of the flow channel orifice. Each time fluid passes through, it gradually guides the airflow to rotate, disperse, and recombine, effectively enhancing the mixing efficiency of natural gas and hydrogen. The horizontally placed baffles are arranged at an angle along the diameter of the flow channel to disrupt the axial flow of the airflow, generating lateral turbulence, thereby increasing the contact area between the two gases and enhancing the mixing effect. The vertically placed baffles further disrupt the radial distribution of the airflow through a staggered arrangement, enhancing the mixing depth and uniformity. This allows for efficient and uniform mixing of natural gas and hydrogen without an external power source, ensuring the reliability and consistency of gas mixing. It can be flexibly adjusted according to different operating conditions, facilitating installation and maintenance. Furthermore, it allows for adjustment of the number of flow channel orifices, the arrangement of mixing units, and the overall size of the device according to specific application requirements, thus adapting to stable operation needs with different flow rates, velocities, input pressures, and gas mixing ratios. It can withstand various input pressures, exhibiting strong pressure resistance and no input pressure limitations. This invention maintains high blending efficiency while minimizing fluid resistance and energy loss, exhibiting significant low pressure loss characteristics and ensuring low pressure loss operation of the system. Simultaneously, the detachable design enhances the adaptability of the device, enabling it to flexibly meet diverse industrial needs, not only improving the device's utilization efficiency but also significantly reducing operating and maintenance costs. These advantages make this invention promising for broad applications and possessing significant technical advantages in natural gas hydrogen blending, industrial gas treatment, and related fields. This invention offers higher mixing efficiency, lower energy loss, and greater flexibility, making it suitable for fields such as natural gas hydrogen blending and industrial gas treatment.

[0023] Furthermore, the two surfaces of the central transverse turbulence layer, the auxiliary transverse turbulence layer, the central vertical turbulence layer, and the auxiliary vertical turbulence layer are all uniformly distributed with dot-like protrusions, which can enhance the turbulence intensity and expand the contact area between the two gases. However, when the flow rate and velocity are large, reducing the height of the protrusions and increasing the spacing between them can reduce the pressure drop and energy loss.

[0024] This invention discloses a method for operating a static mixing device for uniformly mixing natural gas and hydrogen. Natural gas and hydrogen enter the static mixing unit from two independent inlets (natural gas inlet and hydrogen inlet) in the inlet pipe. The gas flow passes through a flow channel through a torsion unit and a turbulence unit. In the torsion unit, semi-circular first and second torsion plates gradually guide the gas flow to rotate, disperse, and recombine, achieving gas stratification and remixing. In the turbulence unit, horizontally placed turbulent elements disrupt the axial flow of the gas flow, generating lateral turbulence. Vertically placed turbulent elements, arranged in a staggered pattern, further disrupt the radial distribution of the gas flow, enhancing the mixing depth and uniformity. This further disrupts the axial and radial flow characteristics of the gas flow, significantly improving the mixing depth and uniformity, thereby ensuring that the natural gas and hydrogen are fully contacted and uniformly mixed within the static mixing unit. The mixed gas is discharged from the outlet, achieving a high-uniformity and high-efficiency mixing effect. This invention overcomes the shortcomings of existing technologies under different flow rates, velocities, input pressures, and gas mixing ratios. It is also applicable to various gas flow rates and mixing ratios, and has broad industrial application value. It can be used in natural gas hydrogen blending, industrial gas mixing, and other related fields. Attached Figure Description

[0025] To more clearly illustrate the technical solutions in the embodiments of the present invention, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0026] Figure 1 This is a model diagram of the static mixing device described in this invention.

[0027] Figure 2 This is a structural diagram of the static mixing device described in this invention.

[0028] Figure 3 yes Figure 2 Enlarged view of the static mixing unit.

[0029] Figure 4a yes Figure 2 Structural diagram of the torsion unit.

[0030] Figure 4b yes Figure 2 Structural diagram of the central turbulence unit.

[0031] Figure 5 This is a diagram showing the mesh division result of the static mixing device provided by the present invention.

[0032] Figure 6a This is a velocity vector cloud map at the XY section position of the first mixing unit on the static mixing device of the present invention.

[0033] Figure 6b This is a velocity vector cloud map at the XY section position of the second mixing unit on the static mixing device of the present invention.

[0034] Figure 6c This is a velocity vector cloud diagram at the YZ section position of the static mixing device described in this invention.

[0035] Figure 7 This is a cloud map showing the distribution of hydrogen molar volume fraction at different XY cross-sectional positions before and after passing through the static mixing device, provided by the present invention.

[0036] Figure 8a This is a schematic diagram of the flow channel hole distribution of the first static mixing unit provided by the present invention.

[0037] Figure 8b This is a schematic diagram of the flow channel hole distribution of the second type of static mixing unit provided by the present invention.

[0038] Figure 8c This is a schematic diagram of the flow channel hole distribution of the third type of static mixing unit provided by the present invention.

[0039] Figure 8d This is a schematic diagram of the flow channel hole distribution of the fourth type of static mixing unit provided by the present invention.

[0040] Figure 8e This is a schematic diagram of the flow channel hole distribution of the fifth type of static mixing unit provided by the present invention.

[0041] Figure 8f This is a schematic diagram of the flow channel hole distribution of the sixth type of static mixing unit provided by the present invention.

[0042] Figure 9a This is a schematic diagram of the first static mixing unit distribution location provided by the present invention.

[0043] Figure 9b This is a schematic diagram of the distribution location of the second type of static mixing unit provided by the present invention.

[0044] Figure 9c This is a schematic diagram of the distribution location of the third static mixing unit provided by the present invention.

[0045] Figure 10a yes Figure 4a Front view of the torsion element.

[0046] Figure 10b yes Figure 4a Left view of the torsion element.

[0047] Figure 10c yes Figure 4aTop view of the torsion element.

[0048] Figure 11a yes Figure 4b A front view of a single structure of the central perturbation element.

[0049] Figure 11b yes Figure 4b A three-dimensional view of a single structure of a central perturbation element.

[0050] Figure 11c yes Figure 4b Another perspective perspective of the single structure of the central perturbation element.

[0051] Figure 11d yes Figure 4b A diagram showing the front and rear fixed assembly of the three aerodynamic elements.

[0052] In the diagram: 1-First pipe, 11-Natural gas inlet, 12-Hydrogen inlet, 13-Outlet, 21-Second pipe, 22-Third pipe, 3-Fourth pipe, 41-First arc-shaped transition section, 42-Second arc-shaped transition section, 51-First flange, 52-Second flange, 53-Third flange, 54-Fourth flange, 6-Bolt hole, 7-Flow channel hole, 8-Static mixing unit, 91-Torsion unit, 92-Break current unit, 93-Horizontal baffle, 94-Vertical baffle, 911-Torsion element, 912-Break current element, 914-First torsion plate, 915-Second torsion plate, 931-Central horizontal baffle layer, 932-Auxiliary horizontal baffle layer, 941-Central vertical baffle layer, 942-Auxiliary vertical baffle layer. Detailed Implementation

[0053] To make the objectives, technical solutions, and advantages of the present invention clearer, the embodiments of the present invention will be described in further detail below with reference to the accompanying drawings.

[0054] It should be noted that the terms "upper," "lower," "left," "right," and similar expressions used in this invention are for illustrative purposes only. Unless otherwise defined, all technical and scientific terms used in this invention have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. The terminology used in this specification is for the purpose of describing particular embodiments only and is not intended to limit the invention.

[0055] This invention provides a novel static mixing device for uniformly mixing natural gas and hydrogen, see [link to relevant documentation]. Figure 1 and Figure 2The core components include an intake pipe, a static mixing unit 8, and an outlet pipe that are connected and fixedly linked in sequence. Specifically, these involve a natural gas inlet 11, a hydrogen inlet 12, a first pipe 1, a second pipe 21, a static mixing unit 8, a third pipe 22, a fourth pipe 3, and an outlet 13. The intake pipes include the first pipe 1 and the fourth pipe 3, both with the same inner and outer diameters, ranging from 20mm to 1200mm. The outlet pipes include the third pipe 22 and the fourth pipe 3. The second pipe 21 and the third pipe 22 have the same inner and outer diameters, ranging from 22mm to 1400mm. The outer diameter of the first pipe 1 is smaller than that of the second pipe 21. Specific standards exist for the allowable flow rate and velocity for each inner diameter. A first arc-shaped transition section 41 is provided at the junction of the first pipe 1 and the second pipe 21. The cross-section of the first arc-shaped transition section 41 is annular, and its inner and outer diameters decrease sequentially from the first pipe 1 to the second pipe 21, forming an arc shape. A second arc-shaped transition section 42 is provided at the junction of the third pipe 22 and the fourth pipe 3. The inner and outer diameters of the second arc-shaped transition section 42 decrease sequentially from the third pipe 22 to the fourth pipe 3, forming an arc shape. The curvature angle of the arcs formed by the outer diameters of the two sections is the same, which can be between 5 degrees and 25 degrees. A natural gas inlet 11 and a hydrogen inlet 12 are provided on the first pipe 1. The hydrogen inlet 12 is perpendicular to the length direction of the first pipe 1, and its inner diameter can be between 15 mm and 800 mm.

[0056] The static mixing unit 8 is a cylindrical, regular triangular prism, regular square prism, or regular hexagonal prism pipe. Both ends are connected to the inlet and outlet pipes via two pairs of aligned flanges. One end of the second pipe 21 is connected to the first flange 51. The two ends of the static mixing unit 8 are respectively fixed with a second flange 52 and a third flange 53. One end of the third pipe 22 is connected to a fourth flange 54. The first flange 51 and the second flange 52 are a pair, and the third flange 53 and the fourth flange 54 are a pair. Several bolt holes 6 are evenly opened along the circumferential direction on the edges of the two pairs of flanges. The number of bolt holes 6 is 6 to 12, and the diameter is 3 to 15 mm. Each bolt hole 6 is equipped with a corresponding bolt to ensure a stable, sealed, and tight connection between the static mixing unit 8 and the inlet and outlet pipes. It can adapt to the needs of various flow rates, gas ratios, and operating conditions.

[0057] The static mixing unit 8 has several flow channel holes 7 extending through both sides of its length. At low flow rates, the hole diameter is 3%-6% of the pipe diameter, and the center-to-center distance between adjacent flow channel holes 7 is 5%-9% of the pipe diameter (or the circumscribed circle diameter for regular triangular, square, or hexagonal prisms). At medium flow rates, the hole diameter is 6%-9% of the pipe diameter, and the center-to-center distance between adjacent flow channel holes 7 is 9%-14% of the pipe diameter. At high flow rates, the hole diameter is 9%-13% of the pipe diameter, and the center-to-center distance between adjacent flow channel holes 7 is 14%-20% of the pipe diameter. The flow channel holes 7 are uniformly distributed along the cross-section of the static mixing unit 8, and their distribution and number can vary in various ways, such as... Figure 8a , Figure 8b , Figure 8c , Figure 8d , Figure 8e and Figure 8f As shown, the number of channels can be 3-17, but to maintain high mixing uniformity, the number of channels should ideally be 5-17. Figure 3 As shown, each flow channel hole 7 has multiple torsion units 91 and turbulence units 92 fixed at intervals on its inner wall. These mixing units ensure that rotation and turbulence are generated during the flow of natural gas and hydrogen under different flow conditions, thereby achieving efficient and thorough mixing. The arrangement of each flow channel hole 7 is highly consistent with the flow path of the gas flow, ensuring that the gas flow achieves a stable and uniform mixing effect when passing through the static mixing unit 8, thereby guaranteeing the optimal mixing efficiency of natural gas and hydrogen.

[0058] like Figure 4a As shown, the torsion unit 91 includes several torsion elements 911 that are sequentially and parallelly overlapped and fixed. The torsion unit 91 is helical in shape, structurally similar to the blades of a propeller. The torsion elements 911 are arranged alternately along the axial direction of the flow channel hole 7. Each torsion element 911 is formed by two semi-circular first torsion plates 914 and second torsion plates 915 (both vertically distributed) of the same diameter, symmetrically and overlapping each other along the central axis of the flow channel hole 7. Specifically, as shown... Figure 10a , Figure 10b and Figure 10c As shown, the center of the straight edge of the first twist plate 914 and the center of the straight edge of the second twist plate 915 are fixed. The angle (twist angle) between the straight edges of the first twist plate 914 and the second twist plate 915 is 30°-45°. The first twist plate 914 is located below, and the angle between the straight edge of the first twist plate 914 and the central axis of the flow channel hole 7 is 45°-65°. The spacing between two adjacent first twist plates 914 or second twist plates 915 is 0.1%-0.8% of the length of the static mixing unit 8. The front end of the straight edge of the second twist plate 915 is fixed to the front end of the straight edge of the previous first twist plate 914, and the rear end of the straight edge of the second twist plate 915 is fixed to the rear end of the straight edge of the next first twist plate 914.

[0059] like Figure 4b As shown, the turbulence unit 92 includes several turbulence elements 912 that are sequentially spliced ​​and fixed together, such as... Figure 11a As shown, each spoiler element 912 includes a horizontal spoiler 93 and a vertical spoiler 94. The horizontal spoiler 93 includes an elliptical central horizontal spoiler layer 931 and auxiliary horizontal spoiler layers 932 symmetrically distributed vertically along the central horizontal spoiler layer 931. The vertical spoiler 94 includes an elliptical central vertical spoiler layer 941 and auxiliary vertical spoiler layers 942 symmetrically distributed vertically along the central vertical spoiler layer 941. Figure 11b and Figure 11c As shown, the major and minor axes of the central horizontal spoiler layer 931 and the central vertical spoiler layer 941 are equal. The auxiliary horizontal spoiler layer 932 and the auxiliary vertical spoiler layer 942 are both single layers. One end of the auxiliary horizontal spoiler layer 932 and the auxiliary vertical spoiler layer 942 are arc-shaped, and the other end of the auxiliary horizontal spoiler layer 932 and the auxiliary vertical spoiler layer 942 are straight. The distances from the two sides to their respective central spoiler layers are different, which can reduce pressure loss. The arc-shaped end of the upper auxiliary horizontal spoiler layer 932 corresponds to the straight end of the lower auxiliary horizontal spoiler layer 932, and the arc-shaped end of the right auxiliary vertical spoiler layer 942 corresponds to the straight end of the left auxiliary vertical spoiler layer 942. The purpose of the horizontal spoiler 93 is to break the axial flow of the airflow and form lateral turbulence, thereby increasing the contact surface of the two gases and enhancing the mixing effect. The vertical spoiler 94 forms a staggered distribution. Their arrangement presents a layered structure, which makes the airflow generate a more complex flow path when passing through, further improving the uniformity of gas mixing. The central transverse spoiler 931, the auxiliary transverse spoiler 932, the central vertical spoiler 941, and the auxiliary vertical spoiler 942 are all composed of several thin sheet-like spoiler strips (i.e. Figure 11b It is composed of rectangular strips with arc-shaped notches at one or both ends, spliced ​​together at intervals. The central horizontal spoiler layer 931 and the central vertical spoiler layer 941 are inserted and fixed perpendicularly to each other along the central axis of the flow channel hole 7. The auxiliary horizontal spoiler layer 932 is smaller than the central horizontal spoiler layer 931 (i.e., its outer edge is inside the central horizontal spoiler layer 931), and the auxiliary vertical spoiler layer 942 is smaller than the central vertical spoiler layer 941.

[0060] like Figure 11d As shown, the foremost spoiler strip of the central vertical spoiler layer 941 in the latter spoiler element 912 is fixed to the rearmost spoiler strip of the central horizontal spoiler layer 931 and the auxiliary horizontal spoiler layer 932 of the former spoiler element 912, so that all the central horizontal spoiler layers 931 and central vertical spoiler layers 941 in the spoiler unit 92 are distributed in a parallel manner.

[0061] In each flow channel 7, each mixing unit maintains a certain spacing (i.e., the spacing between the last element of the previous mixing unit and the first element of the next mixing unit) optimized according to the flow channel diameter and gas flow velocity. This spacing is 6%-13% of the length of the static mixing unit 8. This ensures uniform gas flow distribution while avoiding excessive fluid resistance, ensuring that the gas flow generates a rotational effect as it passes through. Furthermore, the turbulence of the gas flow enhances mixing efficiency, gradually breaking the laminar flow state and promoting initial gas stratification and mixing. Under high flow conditions, this design can effectively break the laminar flow state, resulting in a more uniform initial mixing of natural gas and hydrogen. The torsion element 911 forms a certain angle with the gas flow direction along the flow channel 7, and gradually guides the gas flow to rotate, disperse, and recombine with each fluid passage, thereby effectively enhancing the mixing efficiency of natural gas and hydrogen.

[0062] Each of the turbulence strips has tiny, uniformly distributed dot-like protrusions on both surfaces. These protrusions are present on the surfaces of the central transverse turbulence layer 931, the auxiliary transverse turbulence layer 932, the central vertical turbulence layer 941, and the auxiliary vertical turbulence layer 942. At low flow rates and velocities, fluid turbulence is weak, resulting in poor mixing. In this case, the height of the protrusions can be increased and the spacing reduced to enhance turbulence and improve mixing efficiency. At high flow rates and velocities, fluid turbulence is strong, resulting in better mixing. In this case, the height of the protrusions can be appropriately reduced and the spacing increased to minimize pressure drop and energy loss. The dot-like protrusion design further disrupts airflow stability, increases turbulence intensity and turbulent flow, and promotes uniform mixing of the two gases. This effectively reduces uneven distribution of gas components along the cross-section or length of the pipe, ensuring optimal mixing.

[0063] The types, order, and number of mixing units installed within the flow channel 7 can take many forms, such as... Figure 9a , Figure 9b and Figure 9c As shown, each type of hybrid unit is arranged in an alternating pattern, although the length of each hybrid unit may be different.

[0064] The inner wall of the flow channel hole 7 is provided with internal threads. The first torsion plate 914, the second torsion plate 915, the central horizontal turbulence layer 931, and the central vertical turbulence layer 932 are engaged in the internal threads. This not only fixes the position of all mixing units, but also helps the gas to gain rotational kinetic energy at the same time. It works in synergy with the mixing units to enhance the mixing efficiency of the gas.

[0065] The arc-shaped transition section at the junction of the inlet and outlet pipes enhances the tortuosity of the gas flow path, forcing the airflow along different paths, thereby promoting forced mixing of the two gases and further improving the mixing effect. Multiple changes in flow direction eliminate uneven distribution of gas components along the cross-section or length of the pipe, ensuring thorough mixing of the two gases.

[0066] The static mixing unit 8 and its connected pipes are made of stainless steel or high-strength corrosion-resistant alloy steel to ensure its high temperature resistance, corrosion resistance and stability during long-term operation, so as to adapt to the high temperature and high pressure working environment. During long-term use, the materials will not age, corrode or degrade in performance, ensuring its stability and reliability during long-term operation.

[0067] This invention discloses a static mixing device for uniformly mixing natural gas and hydrogen, the specific assembly process of which is as follows:

[0068] Step 1: As needed, install several torsion units 91 and turbulence units 92 into the flow channel hole 7 in sequence, ensuring that each unit is arranged correctly in order to guarantee the mixing effect and precise control of the airflow path.

[0069] Step 2: Connect the static mixing unit 8 to the inlet and outlet pipes via flanges, and secure the flanges together using bolt holes 6. The bolt holes are used to tighten the flanges with bolts, ensuring the stability and airtightness of the flange connection.

[0070] Step 3: Connect the bolt holes 6 at both ends of the flange with bolts to ensure a secure connection between the flange and the pipeline, allowing airflow to pass smoothly through the static mixing unit 8.

[0071] Step 4: Conduct an overall inspection of the installed static mixing device to confirm that all components are correctly installed and to ensure that the equipment can work smoothly in actual operation.

[0072] CFD simulation can analyze the flow state and characteristics of fluids under high-pressure flow conditions. Through fluid-structure interaction (FSI), the relevant performance characteristics of this invention can be further obtained. Simulation calculations were performed using ANSYS Workbench software, with the FLUENT module selected for flow field calculations. Transient solution was used; the k-ε Realizable turbulence model was chosen; and the fluid materials were specified as methane and hydrogen. Boundary conditions: both inlets were set as velocity inlets, with inlet velocity conditions set to 6 m / s and 12 m / s respectively; the pressure outlet was set as the outlet boundary condition, with a pressure value set to gauge pressure 0 Pa; the boundary type for the FSI interface and symmetry plane was set to wall; the SIMPLE algorithm was used; the time step was set to 1500 steps with a time step size of 0.002 s, and the calculations were performed after initialization according to the following procedure.

[0073] To investigate the characteristics of fluid flow within the device described in this invention, non-flowing components and features that do not affect overall performance were simplified in the 3D mechanical design software SolidWorks. In the numerical simulation, other parts that do not affect fluid flow rate and sealing were simplified, and the pipe walls and connecting flanges of the static mixer device were removed. The model was imported into the Geometry module of the finite element analysis software ANSYS to extract the flow channels, and a tetrahedral mesh was used for mesh generation, with a mesh size of 2.36 million. Figure 5 As shown.

[0074] When the inlet air velocities are 6 m / s and 12 m / s respectively, the velocity vector cloud diagrams on the XY sections of the first and second mixing units of the static mixing device are obtained through simulation, as follows: Figure 6a , Figure 6b As shown; the velocity vector cloud diagram of the YZ interface of the static mixer device is obtained, as follows. Figure 6c As shown.

[0075] Figure 6a The diagram shows the velocity vector cloud map at the XY section of the first mixing unit. Combined with the information that the first mixing unit consists of semi-circular torsion elements, the velocity distribution and vortex structure in the diagram clearly reflect the effect of the torsion elements on the airflow. Multiple vortex regions are visible within each flow channel orifice, indicating significant rotation and disturbance of the airflow as it passes through the semi-circular torsion elements. The design of these torsion elements induces strong vortex flow within the flow channel orifices, effectively breaking the laminar flow and promoting the mixing of natural gas and hydrogen. Regions with higher velocities typically appear near the edges of the flow channel orifices and the torsion elements, while the velocities are lower in the central region of the flow channel. This indicates that the torsion elements, while increasing the rotational kinetic energy of the airflow, also lead to uneven velocity distribution. The combined effect of velocity differences and vortex flow enhances the mixing effect between the two gases, especially under high flow conditions, ensuring efficient and uniform mixing. Overall, the vortex effect generated by the semi-circular torsion elements, by changing the flow direction and velocity of the airflow, helps to break the laminar flow and significantly improves the gas mixing efficiency.

[0076] Figure 6bThe velocity vector cloud diagram at the XY section of the second mixing unit is shown. The diagram reveals that the airflow, influenced by the baffles, exhibits significant turbulence and velocity variations. The color bars represent velocity ranges, from red (maximum velocity 121 m / s) to blue (minimum velocity 0 m / s), indicating substantial velocity differences. The airflow displays complex flow patterns under the longitudinal and transverse arrangement of the baffles. It is evident that the airflow velocity is higher near the baffles, particularly in the region close to them, where the velocity increases significantly, forming localized high-speed airflow areas. Compared to the torsional element in the first mixing unit, the baffles further enhance turbulence intensity by altering the airflow direction and increasing flow complexity. This causes the axial and radial flows of the airflow to interfere with each other, thereby improving the mixing uniformity of natural gas and hydrogen. The enhanced vortex flow and turbulence effectively promote the mixing of the two gases, especially under high flow conditions, helping to break the laminar flow state and achieve more efficient mixing. In summary, the second mixing unit, through its unique baffle design, effectively enhances the turbulence intensity of the airflow and promotes uniform gas mixing.

[0077] Figure 6c The velocity vector cloud diagram at the YZ section of the static mixing device is shown. The velocity distribution of the fluid is represented by color bars, with the red area representing the highest velocity (121 m / s) and the blue area representing the lowest velocity (0 m / s). It can be seen that the flow velocity exhibits significant changes and distribution characteristics after passing through different mixing units and flow channel orifices in the static mixing device. At both ends of the device, the fluid velocity is higher, especially at the outlet region of the flow channel orifice, where the velocity is more concentrated and larger, indicating that the fluid velocity increases after passing through multiple mixing units. In the middle section, especially within the flow channel orifice, the airflow distribution is more uniform, with varying degrees of vortex flow, indicating that the airflow is disturbed and turbulent when passing through the mixing units. This turbulent effect contributes to gas mixing and improves the uniformity of natural gas and hydrogen blending. Regions with large velocity variations are generally related to the shape of the flow channel, the layout of the mixing units, and the interaction between the fluid and the solid surface. These regions promote thorough mixing of the two gases by changing the flow direction and velocity of the fluid. Overall, the velocity distribution in the figure reflects that the static mixing device effectively promotes gas turbulence and uniform mixing through multiple mixing units and flow channel design, and can maintain a high mixing efficiency even under high flow conditions.

[0078] Figure 7The diagram illustrates the change in the molar volume fraction of hydrogen before and after mixing natural gas and hydrogen. Before mixing (before entering static mixing unit 8), the hydrogen distribution in the diagram is significantly uneven, with a higher molar fraction of hydrogen at the top, displayed as red or orange, while other areas have a lower molar fraction, displayed as blue or green, indicating a significant non-uniformity in the hydrogen distribution within the gas. After mixing (just exiting static mixing unit 8), the color of the entire area becomes more uniform, with almost all areas appearing blue, indicating that the molar fraction of hydrogen tends to be consistent throughout the space, showing that the natural gas and hydrogen have been fully mixed. This comparison visually demonstrates the effectiveness of the mixing device in promoting the uniform mixing of hydrogen and natural gas, successfully transforming the non-uniform hydrogen distribution into a uniform state.

[0079] This invention discloses a static mixing device for uniformly mixing natural gas and hydrogen. During operation, the gas flow rate is controlled by external metering equipment. Under different flow rates, velocities, input pressures, and gas mixing ratios, natural gas flows in through the natural gas inlet 11, and hydrogen flows in through the upper hydrogen inlet 12. The inlets (11, 12) work in conjunction with the mixing units within the device to ensure sufficient contact and uniform mixing of the two gases. After passing through multiple units, the mixed gas flows out through the outlet 13. This effectively reduces fluid stratification and maintains efficient gas mixing, thus achieving good mixing results under different flow conditions. The mixed gas maintains good uniformity, ensuring a gas blending uniformity of over 99%.

[0080] The above embodiments are merely illustrative of the technical concept of the present invention and should not be construed as limiting the scope of protection of the present invention. Any modifications made to the technical solution based on the technical concept proposed in this invention shall fall within the scope of protection of this invention.

Claims

1. A static mixing device for mixing natural gas and hydrogen uniformly, characterized by, The static mixing unit (8) is provided with a plurality of flow channel holes (7) along the length direction thereof, and the inner wall of each flow channel hole (7) is fixedly provided with a torsion unit (91) and a turbulence unit (92) at intervals. The torsion unit (91) comprises a plurality of torsion elements (911) fixed in parallel at intervals in front and back, each torsion element (911) is formed by a first torsion sheet (914) and a second torsion sheet (915) fixed in a symmetrical manner above and below the center axis of the flow channel hole (7), and the turbulence unit (92) comprises a plurality of turbulence elements (912) fixed in a symmetrical manner in front and back, each turbulence element (912) comprises a horizontal turbulence element (93) and a vertical turbulence element (94), the horizontal turbulence element (93) comprises an oval central horizontal turbulence layer (931) and auxiliary horizontal turbulence layers (932) symmetrically distributed above and below the central horizontal turbulence layer (931), and the vertical turbulence element (94) comprises an oval central vertical turbulence layer (941) and auxiliary vertical turbulence layers (942) symmetrically distributed above and below the central vertical turbulence layer (941).

2. The static mixing device for homogenous mixing of natural gas with hydrogen as claimed in claim 1 wherein, The first pipeline (1) is provided with a natural gas inlet (11) and a hydrogen gas inlet (12), the outlet pipeline comprises a third pipeline (22) and a fourth pipeline (3), the inner and outer diameters of the first pipeline (1) and the fourth pipeline (3) are the same, the inner and outer diameters of the second pipeline (21) and the third pipeline (22) are the same, the outer diameter of the first pipeline (1) is smaller than the inner diameter of the second pipeline (21), the combination of the first pipeline (1) and the second pipeline (21) is provided with a first arc-shaped transition section (41), the combination of the third pipeline (22) and the fourth pipeline (3) is provided with a second arc-shaped transition section (42), the bending angles of the first arc-shaped transition section (41) and the second arc-shaped transition section (42) are the same, and are 5-25 degrees.

3. The static mixing device for homogenous mixing of natural gas with hydrogen as claimed in claim 1 wherein, The static mixing unit (8) is a cylindrical, right triangular prism, right quadrangular prism or right hexagonal prism pipeline, and the pipeline is fixedly connected with the inlet pipeline and the outlet pipeline through two pairs of aligned flanges at both ends.

4. The static mixing device for uniformly mixing natural gas with hydrogen according to claim 3, wherein The inner wall of the flow channel hole (7) is provided with an internal thread, the first torsion sheet (914) and the second torsion sheet (915) are two semicircular structures with the same diameter, the first torsion sheet (914), the second torsion sheet (915), the central horizontal turbulence layer (931) and the central vertical turbulence layer (941) are clamped in the internal thread. The flow channel holes (7) are uniformly distributed at 3-17 along the cross section of the static mixing unit (8), the hole diameter is 3%-13% of the cross section size of the static mixing unit (8), the center distance of adjacent flow channel holes (7) is 4%-20% of the cross section size of the static mixing unit (8), when the cross section of the static mixing unit (8) is circular, the corresponding size is the diameter, when the cross section of the static mixing unit (8) is equilateral triangle, square and regular hexagon respectively, the corresponding size is the diameter of the circumscribed circle.

5. The static mixing device for homogenizing a mixture of natural gas and hydrogen according to claim 4, characterized in that The first torsion sheet (914) and the second torsion sheet (915) are vertically distributed, the center of the straight edge of the first torsion sheet (914) and the center of the straight edge of the second torsion sheet (915) are fixed, the included angle between the straight edge of the first torsion sheet (914) and the straight edge of the second torsion sheet (915) is 30°-45°, the first torsion sheet (914) is located below, and the included angle between the straight edge of the first torsion sheet (914) and the center axis of the flow channel hole (7) is 45°-65°.

6. The static mixing device for uniformly mixing natural gas with hydrogen according to claim 5, wherein The distance between the two adjacent first torsion sheets (914) or second torsion sheets (915) is 0.1%-0.8% of the length of the static mixing unit (8), the front end of the straight edge of the second torsion sheet (915) is fixed with the front end of the straight edge of the previous first torsion sheet (914), and the rear end of the straight edge of the second torsion sheet (915) is fixed with the rear end of the straight edge of the next first torsion sheet (914).

7. The static mixing device for uniformly mixing natural gas with hydrogen according to claim 1, wherein The two surfaces of the center transverse turbulent flow layer (931), the auxiliary transverse turbulent flow layer (932), the center vertical turbulent flow layer (941) and the auxiliary vertical turbulent flow layer (942) are uniformly distributed with point protrusions.

8. The static mixing device for uniformly mixing natural gas with hydrogen according to claim 1, wherein The center transverse turbulent flow layer (931), the auxiliary transverse turbulent flow layer (932), the center vertical turbulent flow layer (941) and the auxiliary vertical turbulent flow layer (942) are spliced by a plurality of turbulent flow strips, the center transverse turbulent flow layer (931) and the center vertical turbulent flow layer (941) are vertically inserted and fixed along the center axis of the flow channel hole (7); The long and short axes of the center transverse turbulent flow layer (931) and the center vertical turbulent flow layer (941) correspondingly are equal, the auxiliary transverse turbulent flow layer (932) and the auxiliary vertical turbulent flow layer (942) are both one layer, one end of the auxiliary transverse turbulent flow layer (932) and the auxiliary vertical turbulent flow layer (942) is arc-shaped, and the other end of the auxiliary transverse turbulent flow layer (932) and the auxiliary vertical turbulent flow layer (942) is straight, wherein the arc-shaped end of the auxiliary transverse turbulent flow layer (932) on the upper layer corresponds to the straight end of the auxiliary transverse turbulent flow layer (932) on the lower layer, the arc-shaped end of the auxiliary vertical turbulent flow layer (942) on the right side corresponds to the straight end of the auxiliary vertical turbulent flow layer (942) on the left side, the size of the auxiliary transverse turbulent flow layer (932) is smaller than that of the center transverse turbulent flow layer (931), and the size of the auxiliary vertical turbulent flow layer (942) is smaller than that of the center vertical turbulent flow layer (941).

9. The static mixing device for uniformly mixing natural gas with hydrogen according to claim 8, wherein The frontmost turbulence bars of the central vertical turbulence layer (941) of the latter turbulence element (912) are fixed with the rearmost turbulence bars of the central horizontal turbulence layer (931) and the auxiliary horizontal turbulence layer (932) of the former turbulence element (912), and all the central horizontal turbulence layers (931) and the central vertical turbulence layers (941) in the turbulence element (92) are flushly distributed respectively; The interval between the adjacent two twist elements (91) or between the twist element (91) and the turbulence element (92) in each flow hole (7) is 6%-13% of the length of the static mixing element (8).

10. The method of claim 1 to 9, wherein the static mixing device is used for mixing natural gas and hydrogen uniformly, characterized in that, Natural gas and hydrogen gas flow into the static mixing element (8) from the inlet pipe, and then enter the corresponding twist element (91) and turbulence element (92) through each flow hole (7). The first twist sheet (914) and the second twist sheet (915) gradually guide the gas flow to rotate, disperse and recombine. The horizontal turbulence element (93) disturbs the axial flow of the gas flow to generate transverse turbulent flow. The vertical turbulence element (94) further disturbs the radial distribution of the gas flow by staggered arrangement to enhance the depth and uniformity of the mixing. The natural gas and hydrogen gas are fully contacted and uniformly mixed in the static mixing element (8). The mixed gas flows out of the outlet pipe to realize the efficient and uniform mixing of natural gas and hydrogen gas.

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